Conventionally, a drug bag containing a drug such as infusion solution for administering it to a patient is known.
FIG. 14 is a schematic exploded perspective view of a conventional typical drug bag. As shown in FIG. 14, a drug bag 200 has a drug bag body 202 with a compartment 201 containing a drug such as an infusion solution, and a plastic tubular port member 203 communicating the compartment 201 with the exterior of the drug bag 200 to discharge the drug. The port member 203 is normally closed by a rubber plug 204, but when the drug is administered to a patient, the port member 203 is opened by penetrating a hollow infusion needle through the rubber plug 204.
The drug bag body 202 is formed by fusion-bonding peripheral portions of two plastic films 205a, 205b to each other so as to form the compartment 201. Further, the port member 203 is sandwiched between the two plastic films 205a, 205b and fusion-bonded to the two plastic films 205a, 205b. These fusion-bonding processes are generally performed by means of a heat-sealing process explained below.
FIG. 15 is a view for explaining the fusion-bonding process at the peripheral portions of the two plastic films. As shown in FIG. 15, heated sealing molds 206 are disposed on the opposed sides of the two plastic films 205a, 205b (see FIG. 15(a)), the sealing molds 206 are pressed against the two plastic films 205a, 205b to melt the two plastic films 205a, 205b at the same time (see FIG. 15 (b)), and the two plastic films 205a, 205b are fusion-bonded to each other (see FIG. 15 (c)).
FIG. 16 is a view for explaining the fusion-bonding process between the two plastic films and the port member. As shown in FIG. 16, after the port member 203 is inserted between the two plastic films 205a, 205b, heated sealing molds 207 are disposed on the opposite sides of the two plastic films 205a, 205b (see FIG. 16 (a)), the sealing molds 207 are pressed against the two plastic film 205a, 205b (see FIG. 16 (b)), and the plastic films 205a, 205b and the port member 203 are fusion-bonded to each other (see FIG. 16 (c)).
However, although the two plastic films 205a, 205b become a melted state by means of the sealing molds 207 right after the press action thereof, since the sealing molds 207 do not contact the port member 203, a surface of the port member 205 becomes a melted state later due to a heat conducted through the two plastic films 205a, 205b. Thus, while the surface of the port member 203 becomes the melted state, the two plastic films 205a, 205b become an excess melted state. As a result, although the two plastic films 205a, 205b and the port member 203 are fusion-bonded to each other, damage is caused around the fusion-bonded location 208 of the plastic films 205a, 205b, and concretely portion around the fusion-bonded location 208 are raised or become dirty (see FIG. 16 (c)). Thus, by inserting the port member 203 between the two plastic films 205a, 205b after the port member 203 is preheated, the plastic films 205a, 205b and the port member 203 become the melted states at the same time so that the damage can be avoided (see FIG. 16 (d)).
On the other hand, a technology is known of using a laser beam in the process of fusion-bonding the peripheral portions of the two plastic films 205a, 205b (please refer to the Patent Publication 1 indicated later). FIG. 17 is a view for explaining a fusion-bonding process disclosed in the Patent Publication 1. As shown in FIG. 17, a heat generating member 208 generating heat by absorbing a laser beam is disposed under the two plastic films 205a, 205b, the two plastic films 205a, 205b are pressed from an upper side thereof by a transparent holding member 209, the laser beam L is irradiated to the heat generating member 208 through the holding member 209 and the two plastic films 105a, 205b, and heat generated by the heat generating member 208 allows the two plastic films 205a, 205b to become a melted state and fusion-bond to each other.    [Patent Publication 1] Japanese Patent Laid-open Publication No. 2004-142225